Safety Assessment of Genetically Modified Foods and Food Additives in Korea

Kim, Chang-Min The Korean Society of Toxicology Korea Environment 2001 Toxicological Research Vol.17 No.-

Genetically modified foods and food additives are derived from organisms that have been inserted foreign genetic materials by recombinant DNA techniques to improve the quality or any other pur-poses. The problems such as toxicity, allergenicity and antibiotics resistance in the safety of genetically modified foods are usually concerned. In Korea, the safety of foods is ensured by the Food Sanitation Act. Although there is no specific provision regarding the genetically modified foods in it, any foods that might cause negative effect(s) on public health or human life are prohibited to sell in the market. In order to systematically evaluate safety of genetically modified foods, the Korea Food and Drug Administration (KFDA) promulgated "Guidelines regarding review of safety assessment data for genetically modified foods and food additives (KFDA Notification 1999-46)". The objectives of these guidelines are to ensure safety of genetically modified foods and food additives. In order to evaluate the safety of genetically modified foods. KFDA operates a special expert committee composed by experts from government, universities, research institutes. and consumer's unions. Recently. manufacturers and consumers are interested in the issues on safety and labeling of genetically modified foods, because of increment of imported genetically modified crops and processed foods. Since government and consumers unions have different viewpoints, their positions regarding the issue are different each other. Therefore, the regulation of labeling on genetically modified foods is prepared and should be enforced at July 2000 in Korea. in Korea.

Current Situation of the International Recognition of Toxicologists -Update of the Japanese Society of Toxicology-

Horii, Ikuo The Korean Society of Toxicology Korea Environment 2001 Toxicological Research Vol.17 No.-

Issuance of certification and licensing for toxicologists authorized by the Japanese Society of Thxicology (JST) became effective on July 24, 1997. The certification system consists of examination, eligibility requirements for the applicants, authorization/license by the board of trustees of JST, and the re-certification of previously authorized qualification. In the last 2-3 years, about 30-40% of candidates for the examination have succeeded. The Committee has estimated that the level of the examination would be sufficient to determine qualified toxicologists. This updated status and a detailed explanation are to be presented at the workshop. In global terms, the JST special committee agrees that "harmonization of certification/registration procedure for qualified toxicologists means to ensure/set the minimum requirement for the global authorization of qualified toxicologists". The following items in global authorization are ad-dressed for further discussion: (1) What's the benefit\ulcorner (2) Toxicological safety assessment standards, and (3) the JST position for authorization.orization.

International Harmonization of Accreditation of Toxicologists

Satoh, Tetsuo The Korean Society of Toxicology Korea Environment 2001 Toxicological Research Vol.17 No.-

In the past, IUTOX engaged in dialogue with various international toxicology organizations to address this important issue. IUTOX Executive Committee engaged in activities that support accreditation and/or registration of toxicologists around the world. As a result of discussions held during the IUTOX-sponsored workshop at the 2000 Annual Meeting of the SOT in Philadelphia, it was decided to create an international forum, the "International Assembly for the Recognition of Toxicologists"(IART). The mission of IART was defined as threefold: 1) to establish a forum for development of criteria for recognizing qualified experts in toxicology; 2) to assist "recognizing organizations" in establishing these criteria; and 3) to promote identification and training needs to enhance expertise in toxicology. The membership of IART is open to all organizations (e.g., registries, boards, academies, etc.) whose purpose is the recognition of expertise in toxicology.rtise in toxicology.

Future of Toxicology and Role of Asian Chemical Safety Network

Kaminuma, Tsuguchika The Korean Society of Toxicology Korea Environment 2001 Toxicological Research Vol.17 No.-

Toxicology is under challenge from several new trends in science and technology, namely computer, the Internet, genome projects, genomic technologies, and combinatorial chemistry. These new trends will drastically change research style of toxicology. In addition to conventional uni cellular tests and animal tests using rodents, computer simulation, DNA chips (microarrays), in vivo tests using simple model organisms such as nematodesor flies become important routine screening tests. How to arrange these tests in tiers will become a new problem. Endocrine disruptors hypothesis is a good example for this kind of futuristic approach. Computer, particularly the Internet, is also enabling toxicologists and regulatory experts to collaborate more closely. The IPCS (International Program for Chemical Safety) which is ajoint project of WHO, ILO and UNEP, is a well-known international collaborative research for chemical risk assessments. The GINC project of IPCS is an effort to utilize the Internet for such collaborations. Some efforts were also made to establish regional collaboration network in East Asia under this project.

Free Radical Toxicology and Cancer Chemoprevention

Lin, Jen-Kun The Korean Society of Toxicology Korea Environment 2001 Toxicological Research Vol.17 No.-

Most reactive oxygen species (ROS) are free radicals and implicated in the development of a number of disease processes including artherosclerosis, neurodegenerative disorders, aging and cancer. ROS are byproducts of a number of in vivo metabolic processes and are formed deliberately as part of nor-mal inflammatory response. On the other hand, ROS are generated either as by products of oxygen reduction during xenobiotic metabolism or are liberated as the result of the futile redox cycling of the chemical agents including several chemical carcinogens. A better understanding of the mechanisms of free radical toxicity may yield valuable clue to risks associated with chemical exposures that leading to the development of chronic diseases including cancer. The molecular biology of ROS-mediated alterations in gene expression, signal transduction and carcinognesis is one of the important subjects in free radical toxicology. Epidemiological studies suggest that high intake of vegetables and fruits are associated with the low incidence of human cancer. Many phytopolyphenols such as tea polyphenols, curcumin, resveratrol, apigenin, genistein and other flavonoids have been shown to be cancer chemopreventive agents. Most of these compounds are strong antioxidant and ROS scavengers in vitro and effective inducers of antioxidant enzymes such as superoxide dismutatse, catalase and glutathione peroxidase in vivo. Several cellular transducers namely receptor tyrosine kinase, protein kinase C, MAPK, PI3K, c-jun, c-fos, c-myc, NFkB, IkB kinase, iNOS, COX-2, Bcl-2, Bax, etc have been shown to be actively modulated by phyto-polyphenols. Recent development in free radical toxicology have provided strong basis for understanding the action mechanisms of cancer chemoprevention.

Non-polar Solvents (Toluene and Styrene) Enhance Methanol Skin Absorption

Lim, Cheol-Hong,Yu, Il-Je The Korean Society of Toxicology Korea Environment 2001 Toxicological Research Vol.17 No.1

The quantitative assessment of the penetration of organic solvents through skin is necessary for the evaluation of health hazards in occupational environments. We investigated the rate of dermal penetration when mixed or single forms of organic solvents were placed into a diffusion cell in vitro or into an experimental animal in vivo. The diffusion rates of methanol. toluene, and styrene were 6.07, 0.129, and 0.046 mg/$cm^2$/h, respectively. When skin was exposed to the mixed solvent of methanol and toluene, the penetration rate of toluene did not change significantly (0.110 mg/$cm^2$/h). However, the rate of methanol penetration increased to 43.90 mg/$\textrm{cm}^2$/h. The penetration rate of methanol also increased significantly to 54.69 mg/$cm^2$/h by mixing it with styrene. The concentration of methanol in the blood was monitored during the epicutaneous exposure in rats. The blood concentration of methanol was increased by mixing methanol with toluene as seen in the in vitro experiments. These results showed that the penetration rate of organic solvents would be enhanced by mixing them with other solvents.

An Approach to Detect Health Risk of Dioxins

Pavittranon, Sumol,Sinhaseni, Palarp The Korean Society of Toxicology Korea Environment 2001 Toxicological Research Vol.17 No.-

March 19, 1999, the renovation qf the runway of the Bo-Fai ai1field in Hua Hin, Prachubk-erikhan, Thailand, unearthed chemicals which were left over from the project "anch Hand Operation" held during the Vietnam war era. The chemical mixtures were analyzed by the US EPA, the Department oj Medical Sciences (DMSc), Ministry oj Public Health (MoPH) and the Pollution Control Department (PCD), the Ministry oj Science Technology and Environment (MOSTE) of Thailand, The samples were found to contain several defoliants used in the operation. They were 2,4-D, 2,4,5-T, Dicamba, Cocydelic acid, and Dioxins. Due to the complexity of the issue, the multiplicity of possible health effects, and the socio-economic implications for imports and exports, the Thai Society of Toxicology submitted a proposal to request World Health Organization (WHO), Geneva. The assistance is for the area of chemical safety and called for immediate action to explore the magnitude qf risk involved with Dioxins. In this paper we present our approach to health risk assessment which takes into an account the epidemiological studies of high-risk group exposed to the Ranch Hand operation. Dioxins are endocrine disruption chemicals which public concerns are developed due to presumption that a hazard exists (www.eva.gov/dioxins/html) for which current methodologies are deemed insufficient. The recent concepts of how oxidative stress toxicants may affect health end points and biomarkers of exposure of exposed individuals are discussed. While research activities are undergoing, The Thai Society of Toxicology do not anticipate significant risk to local residents and the environment due to our concurrence with opinion from the international experts invited by the World Health Organization proposed to the local experts at a workshop in Bangkok.n Bangkok.

PRESENT STATUS OF MYCOTOXIN STUDIES IN KOREA

Lee, Su-Rae The Korean Society of Toxicology Korea Environment 1985 Toxicological Research Vol.1 No.1

Mycotoxins are a group of toxicants giving a risk potential to human health in connection with the daily food intake. Food commodities once contaminated with mycotoxins can not be detoxified by any economic means and prevention was suggested as the only measure. In order to minimize the economic loss and health hazard posed by mycotoxins and toxicoses, systematic and toxicological studies on the subject should be undertaken. Most reports in Korea were concentrated on the mycological studies of relatively easy techniques and the confirmation or quantitation of mycotoxins was rarely done. Research topics to be undertaken in future may be exemplifid below: (1) Establishing assay methods for individual or multi-residue of mycotoxins (2) Monitoring of mycotoxins for suspicious food or feed samples in Korea (3) Epidemiological survey of mycotoxicoses (4) Etiological survey of disease outbreaks associated with mycotoxins (5) Accumulation of testing method and data on the toxicity of mycotoxins (6) Legal regulation to control mycotoxins and development of their detoxification / elimination methods

EFFECTS OF MAILLARD-TYPE PRODUCTS ON SERUM ENZYMES IN RATS AND ON MUTAGENICITY IN SALMONELLA TYPHIMURIUM

Yang, Kwang-Kyu,Moon, Ja-Yeong,Park, Ki-Hyun The Korean Society of Toxicology Korea Environment 1987 Toxicological Research Vol.3 No.2

The Maillard reaction products between amino acids and sugars are used effectively as flavors for processed foods and tobacco. Recently, considerable attention has been focused on the toxicological effects of maillard browned compounds. Therefore, we have tested the safety on the three-types of Maillard products (KG-19, KG-24 and KG-32) prepared from this Research Institute. Throughout the observation period of the acute toxicity study in rats and the mutagenicity assay using Salmonella typhimurium (TA98, TA100), the test articles did not show any sigificant toxic or mutagenic signs.

PROTECTIVE ACTION OF N-ACETYLCYSTEINE AGAINST HEPATOTOXIC AGENTS IN ISOLATED RAT LIVER CELLS

Park, Soo-Hee,Dong, Mi-Sook,Kang, Dong-Chul,Lee, Ki-Wan,Cha, Young-Nam The Korean Society of Toxicology Korea Environment 1987 Toxicological Research Vol.3 No.2

Hepatocytes isolated from rats which have been pretreated with phenobarbital (80 mg/kg for 3 days), were able to take up N-acetylcysteine from surrounding medium and were able to synthesize the reduced glutathione ($GSH^{\ast}-3$) intracellularly. The N-acetylcysteine is quickly deacetylated after the uptake and increases the pool size of cysteine, which was very low initially (5 nmol/$10^6$ cells). From this increased intracellular cysteine pool, GSH was synthesized. Freshly isolated rat hepatocytes contained a high level of GSH (30 nmol/$10^6$ cells), but upon incubation with the diethylmaleate, it was markedly decreased (10 nmol/$10^6$ cells). The hepatocytes with depleted GSH have lost viability upon incubations with acetaminophen (5mM) and paraquat (2 mM). However, when the N-acetylcysteine (1 mM) was added to this incubation condition, these chemical induced hepatocellular necrosis were prevented for longer durations. This N-acetylcysteine dependent protective effect against the hepatotoxic chemicals was lost by adding methionine sulfoximine (10 mM), an inhibitor of GSH biosynthesis. Both the carbontetrachloride (5 mM) and chioroform (5 mM) added to the incubation medium caused rapid losses of GSH and cell viability, even without the prior depletion of cellular GSH. However, again, if the 1mM N-acetylcysteine was supplemented, the rates of losses of GSH and cell viability were retarded in both cases. Even though large amounts of the added N-acetylcysteine was present in the cell, N-acetylcysteine conjugate of acetaminophen was not formed. Instead, only large amounts of GSH conjugate of the drug was produced. Thus, it is concluded that the added N-acetylcysteine is taken up and utilized for resynthesis of GSH. In turn, this resynthesized GSH contributes to the protection against cytotoxicity inducible with hepatotoxic drugs.